Tracker mechanism for musical instruments



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May 8, 1928.

L. s. LocKwooD TRACKER MEcHANTsM Fon MUSICAL INSTRUMENTS ini Patented May 8, i928.

Unirse stares PATENT OFFICE.-

Loots s. Locrrivoon, or nenas-z ron'awenne., New venir, .essrenon To THE RU- nonrrr 'wnnnrrznn Marini-screams corarenv, er Noemi TONAWANDA, NEW

YGR'K, A COtlDOR/ATON OF NEVI TRACKER EElC'i- .iNEM E MTJSCAL INSTRUMENTS.

application atea apra so, leer.

The object of this invention is the provision of a reliable compensating' tracker mechanism which Will automatically inaintain proper registration or the niusic sheet pertorations with the tracker ducts under all conditions, 1Whether the sheettends bodily to deviate troni its central tracking position or expands or contracts niore or less under atmospheric changes, the improved tracking mechanism being especially desirable for comparatively wide inusic rolls such as roquired 'for orchestral and movingpicture organs.

In the accompanying drawings :W

Figure l is a front elevation oll the traclrer mechanism. Figure 2 is an enlargetrear elevation, partly in section, of the sectional tracker and its conipensatinr devices. ure 3 is atop plan vievv of the tracker niechanism. Figure l is an enlarged cross section on line i-Jl, 1. Figure 5 is an enlarged sectional elevation of the pneunia'tics, the electric switches, the planes of the sectional portions being on line 'ti-5, Figure 6 is a sectional perspective vieiv of the lastinentioned parts. Figure 7 is a diagram ot the tlierinostatic units and their pneumatically-controlled switches.

Similar characters. or reference indicate corresponding parts throughout the several views.

The tracker bo: or traine l0 may be o'l ordinary construction. 'lhe tracker is eapansible and contract-ible and composed ot a suitable number or sections, preterably three, the end sections ll and i8 olf which are movable relatively to the central section 12. rlhese several sections are-also nievable collectively in a lateral direction so that the tracker may be shifted bodily to correct tault.Y registration of the. niusic sheet le shown by dotted lines in Fig. l. For this purpose, the tracker-sections are mounted on a laterally-sliding carriage which in the construction shorvn7 comprises parallel horizontal bars 'i5 tied together a their ends bv cross hars 16. The latter slides on guides l? in the torni oiC horizontalrods parallel with the bars l5 and tired at their ends in the checlrs oit the tracker box. iThe tracker-sections have longitudinal guide-grooves 18 which receive the carriego-bars 15.

lneuniatic mechanism is preferably employedv tor shifting the tracker-carriage, that illustrated by way ot example including a pair ot oppositely-acting` pneuinatics i9, 2O troni either olf which motion is transinitted to the carriage by a lever 21 and linlrs 22, 23. rlhe lower link 22 also serves as a rigid coupling-bar between the movable boards ct the pneumatica 19, 20. A spring 2l Whose it'ree upper end interloclrs With a notch ot the link 22 tends toi return the latter and the movable boards ot said pneuniatics to their normal position. These pneuniatics are applied to opposite sides of a duct-board 2S having` a niain suction pas- Q' (Figs. 5 and (S) Whose upper end is connected by a tube 28 with the main exhaust chaniber oll a niusical instrument, not shown, While the lower end ol said passage leads by a cross-passage 29 to the interior of both pneuinatics 19, 20, said cross passage containingbleeds 30. .in the upper part of 'the blocl; are vertical flushing passages 3l having horizontal extensions 32 from which branches 83 lead into the pneuniatics 19 and E20, respectively. Leading to the flushing passages 3l are tubes Sil, 35 preferably having their inlets arranged adjacent to the paths ot travel ot opposite edges of the niusic sheet. 'llo these inlets are applied valves or pallets 36, carried by the rear arms oit controllinglevers 3?, the liront arnis 38 oit Which constitute laterally-swinging linadapted to bear against or lie adjacent to the edges ot the niusic sheet. These tinger levers are tulcruined on brackets 39 secured to the bacl: ot the end tracker-sections. Light springs l0 tend to'close the ilu'shing valves 36.

rlhe niechanisi'n so tar described operates to shiitt the tracker carriage and the sectional tracker bodily relatively to the music roll, (not shown) to automatically center the niusical sheet to correct faulty registration ot .its pertorations with the trackerducts.

'.lhe mechanism for automatically adjustingr or lengthening or shorteningthe tracker' to compensate tor transverse expansion 'or contraction ot the music sheet due to cliniatic or atmospheric influences is preferably constructed as follows- Arranged above and below the tracker are thermostatic rods or members al each xed at one end in one of the tracker-box cheeks by a set screw l2 or other suitable means, while its opposite end is free and operatively connected with one of the movable tracker-sections ll or 13 by a laterallyswinging lever 43, so that las the rods shorten or lengthen, they shift the end tracker-sections simultaneously toward or from the fixed section, the two rods being mounted to expand in opposite directions i'or this purpose, as shown in Fig. 2. Each of the levers 43 is pivoted to the adjacent tracker box cheeks and its forked inner end is pivotally connected to the tracker-section byV a pin 44, the companion ythermostatic yrod ell being pivoted to the lever near its ulcrum to multiply the movement of the tracker-section. An electric heating coil a5 is applied to each ot the thermostatic rods and these coils are included in a suitable heating circuit, Fig. 7, containy ing automatically-controlled switches generally designated 46, two being employed rin the particular embodimentl or the invention herein shown and described. The fixed members a7 of these switches may be cariied by blocks 48 secured to opposite sides of thel duct-board 26,.wliile their movable members 49'are secured lto the movable boards of auxiliary or switch pneumatics 50, 5l applied to opposite sides of said duct-board, the heating circuit being closed when both ot' said auxiliary pneuinatics are inflated, as shown in F ig. l, and being broken when either of those pneumatic-s is collapsed. The latter, which may be smaller than the power pneumatics 19, 20, communicate by branchpassages 52 with the passages 32. As the smaller auxiliary pneumatics communicate with the interior of the motor pneumatics by the passage 52, 32, and 33, those small pneumatics are exhausted through the motor pneumatic-s and areV usliedthrough the tubes 3a, 35, when the flushing valves 36 are opened by the action of the music sheet on the valve fingers 38.

`rThe operation of the tracking mechanism is as follows Upon starting the instrument to which the mechanism is applied, the-main controlling pneumatics 19, 20 are exhausted by their communication with the exhaust chamber hereinbetore referred to, but they are kept distendedby the link 22 so long as the music sheet remains in its normal, properly-tracking position. However, the switch pneumatics 50, 5l being connected with the suction-source through said main pneumatics,

are collapsed under these conditions, as shown by dotted lines in Fig. l, thus opening the switches 47, 49 and breaking the heating circuit. At the same time the flushing valvesare closed, their lingers 38 reiniaining undisturbed. Should the sheet swerve bodcorresponding matic, destroying the equalized partial vacuum in the two main pneumatics and'allowing the right-hand one to collapse, causing vthe tracker carriage with the tracker to be shifted as a `unit in the opposite direction, by the links 22 and 23 and the lever 2l and restoring the proper registration between the sheet-perforations and the tracker ducts, in a Well-known manner.

When the. music sheet swells or expands under atmospheric inlluences, its edges trip the lingers and open the valves 36, flushing and expandingboth switch pneumatics and closing the heating circuit. The coils thereupon heat the thermostatic rods al, expanding them and shifting the movable tracker sections away from the fixed tracker section accordingly or proportionately to compensate for the expansion of the sheet and maintain it and the tracker in proper register. When the sheet contracts, the fingers are released and the flush valves are allowed -to close under the action of their springs, thus again collapsing the switch pneumatics, opening the switches and breaking the heating circuit. The thermostatic rods are now allowed to cool and contract, thereby shitting the movable tracker-sections` toward the fixed section to follow up the shrinking ot the sheet. In this manner, the sectional tracker is lengthened or shortened automatically, the heating-circuit being either broken or established by the variations or iiuctuations in the width of the sheet, thus maintaining the proper relation between the sheet and the tracker under all conditions.

Originally, the sections oi' the tracker and associated parts are so assembled and adjusted that the tracker is somewhat shorter than the width of a normal music sheet or roll, in order to cooperate properly with a shrunken roll. Therefore, upon putting a roll of normal width in the tracker box, the thermostatic elements come into play teml porarily, and as they are automatically conl claim as my invention l. Tracker mechanism for automaticl musical instruments, comprising an expansible tracker, and thermostatic means under control of the music sheet torautomatically adjusting the length of the tracker tovariations in the width of the sheet. i

Lceasi trol ot a music sheet, for automatically moving the tracker-sections to lengthen or shorten the tracker in accordance with the expansion or contraction of the music sheet- 4. Tracker` mechanism tor automatic musical instruments, comprising an expansible tracker, and means tor automatically adjusting the length ot the tracker including a thermostatic member operatively connected with the tracker, an electric circuit, a heater for said thermostatic member arranged in said circuit, and controlling means for said circuit under control ot the music sheet.

Tracker mechanism for automatic musical instruments, comprising an expansible tracker, and means for automatically adjusting the length of the tracker, includingav thermostatic member operativelyv connected with the tracker and having a heating coil, an electric circuit containing said coil, and a switch in said circuit controlled by the music sheet.

5. Tracker mechanism tor automatic musical instruments, comprising an expansiblc tracker, means for automatically adjusting' the length of the tracker including a thermostatic member having an electric heating coil, a circuit containing said coil, a switch in said circuit, and a controlling pneumatic for said switch under control of the music sheet.

7. Tracker mechanism tor automatic musical instruments, comprising an expansible tracker, means tor automatically adjusting the length ot the tracker including a thermostatic member having an electric heating coil, a circuit containing said coil, a switch in said circuit, a controlling pneumatic for said switch, a conduit communicating with said pneumatic and having ay flushing valve, and means under control ot the music sheet for controlling said flushing valve.

8. Tracker mechanism tor automatic musical instruments, comprising a. tracker having relatively-movable sections, and means under control ot the music sheet tor automatically adjusting the. tracker-sections, said means including thermostatic rods operatively connected with different sections, respectively and mounted to expand lengthwise in opposite directions.

9. Tracker mechanism for automatic musical instruments, comprising a tracker having a fixed section and adjustable sections movable toward and from the fixed sect-ion, therinostatic rods mounted to expand lengthwise in opposite directions and each operatively connected with one ct said adjustable sections, and heating means Jfor said rod under control ot the music sheet.

l0. In tracker mechanism tor automatic musical instruments, an expansible tracker having relatively movable sections, a shiftlever connected to one ot the sections, and a thermostatic rod iixed at one end and having its tree end pivotally connected to said lever.

LOUIS S. LOCKWOOD. 

